Electric zinc-furnace with integral condenser.



v 3 is a partial top plan View, as

`zontal planes D, D1,

JOHN' THOMSQN, OF NEW YORK, N. Y,

ELECTRIC ZINC-FURNACE WITH NTEGRAL CCTNDENSER.

.Specica'cion of Letters Patent.

PatentcdDee. 9, 1913..

Application led .Tnuary .2, 1913.k Serial No. '339,789.

To ail -whom it ma concem:

Be it known that I, JOHN THOMSON, .a citizen ofthe United States, and a resident of the borough of Manhattan ofthe city of New York, in the county and State of New York, have invented certain new and useful Improvements in Electric Zinc-Furnaces with Integral Condnsers, of which the following is a specilication, reference being made to the accompanying drawings, forming a part hereof. l

This invention relates to the metallurgy of zinc, having for its object the production of zinc fumes by thermo-chemical reaction, and then condensing the fume to liquid metal.

The particular means for attaining the desired results, and such an elucidation of the general principles applicable thereto as seem necessary -.tor a complete disclosure, will be pointed out in; connection with the description of the accompanying drawings; which represent one form of embodiment of the invention. o

Figure l is a transverse center section of the furnace, viewed either right or left, as A, A1, of-Fig. Q; Fig. 2 on the left hand side of its center line 1s a vertical longitudinal section as on either the line l, or B1, while that ortion onthe right hand side of its center line is a vertical longitudinal ccntersection, as C, or C1, of Fig. l; and Fig.

on the horiof Fig. 1. .The classer kind of material particularly intended to be treated in this'turnace, (but it is not necessarily restricted thereto) is either igneous oxid of zinc or roasted suliids' combined with carbon as the reagent, whereby, when adequately heated substantially the following representative reaction ensues,

namely: ZnO-l--Cr-Zn-PCO. lf pure ,Zn and C- are used, in recisely correctrelative proportions, then t ie answer of the above formula is -an exact expression of the rel-y sult, in that all of y,the charged material would be volatilized as zinc fume and monoxid of ca rbon,`.whence there would be no residue; but such conditions do not ob# that moreel" tain in commercial practice in less of inert. residual matter will remain, de= pending upon the purity of the materials employed when the formula becomes, as stated, 'simply representative.

Moreover,

lnea'th the resistors. ,of rods may either bo to nell. from the presence of residual matter is a cause of difficulty in realizinga successful result.

The heat necessary for decomposing the charge is derived from an electric current passed through a resistor formed of rods, principally carbon, interposed between terminals, or as it is commonly termed, ai rodresistor, which is so constructed and disposed that the charge is acted upon by radiant energy. Two of such resistorsll, H1, are preferably employed., each being interpolated between carbon connectors, as 5, to which the current is conducted by terminals, as 6, received from copper electrodes 7, ".7". The connectors are set to the natural angle, 30 from the vertical, to which the sta ggercd rods conform, as shown in Fig. 2. These resistors may bc electrified from separate circuits, or in parallel, or in series, as may the lower serios of rods rest on refractory' 'ljhis 'leaves a large portion supports, as S. of the lower series of rods exposed, and it is from these, between the supports, that the heat is transmitted downwardly. by radiation, to the charge. The object of the wedgelikc section, with the broader portion beneath, i density along the horizontal zone `from which the heat is exhausted by the charge. A still further augmentation ol current ldensit may be eli'echd by using ,graphite rods Ior one or a plurality ot (he lower scriss, while those above are ot :unoi'phous carbon.

If air or CC', is iuirmiiuod or 'formell belhon the lowurniosl;

ro-c talliZ/d carhoruwluni gtif), or f" carbon rods may be cooled. with willnot 'De decomposed by the agents named. Suchfrods will of cou be somewhat nonconductive ,of eloclroily. but they will yet he rather good conductors ot heat. The diminution of current therethrough will, however, he fully compensuled by the use ot an overlying series or graphite ro Moreover, the space 9, within the hrec-sided re i phitc or o., Sill; which Y.

is to produce a greater currentv weones. if;

ings as 24, formed by a series of spaced longitudinal'rods 25 and spacedtransverse rods 26, the rods in alternate series being preferably set so that the rods in one set are located'below the 'spaces between the in the other series, in other words., in. al staff; gered relationship. These rods may. prefer ably be of graphite or amorphous carbon. According to the foregoing conditions otasloseinblage of the rods, the fume and gas are necessarily caused to directly in'iping'e from one. series. of openings` upon another series of rods, thence being'successiifely split and' deflected according to the number ot series employed. a

The lowest-series otrodsf27 are setfclose together, thereby forming a chamber or channel` 28 having exits therefrom at its yends as through the openingsor port-s 29. 2O Beneath this'lowest series of rods is the zinc receptacle 30. Thus the traverse et. fume and gas must follow the courses indi cated by the {low-arrows, that is down through the staggered openings to the chan- ,25 nel 28, thence right and left to the exits.

29 therefrom, and then into the zine receptacle at each end thereof, and inally passing rightand left toward its center. Botas the lowest series of rods areA simply set side by 30 side and as they are not ordinarily produced with accuracy, either as to diameters or straightness, there is thus a large number ol narrow slits through. which some ot' the fume and gas and nearly all ofthe Zinc conw desed above will pass; consequently the flow from the end ports 29 and along the zinc receptacle will virtually be through a series of showers of liquid Tzinc-drops, a condition which is conducive to condensation.

The battery of staggered rods supported by plates 31 which rest upon the lowest series of rods and these in turn are snpported by plates 32'whch are immersed the zinc bath R Whose temperature is controlled byl the underlyingchamber S, either bj." natural radiation thereto or by forced circulation of heat or cold air. a constant and wide difference of temperature is maintained betweenv the top and, i0 bottom of the condensing. chamber, 'and the said difference of temperature is in con-- stantly progressive increments from .high to low. Under theseconditions 'the oil' condensation may be very high and be more or less adapted to the rate o.. ous evolution at the resistors.4

' If the condensation is complete then only- CO will remainand this is educted 'roin il ports 33, 331, to right and left hand or chambers T, T1, from whence the .is delivered to atmosphere as by means of pipes 34, 34% But if the condensation. is not complete within the zinc chamber then any residual fume will be precipitated as metal In this 1 Wise' or blue-powder, or oxid, within the side chambers or the pipes. Under normal conditions the C@ which enters the side chambers 'will have?. temperature ot say troni 9000 to '1100" F. and may perhaps maintain a teni perature in the inner walls thereof oit' from say G"n to GOOo which serves the .lsel'ul purpose of conservingl the heat in the superiniposed hearths.

)It may be necessary under certain conditions and possibly desirable in the bulk ol" cases, to apply a .layer of broken carbon, as coke, 35, upon the upper series of condenser rods, also to provide terminals 3G whereby electric current can be passed through this bed of carbon resistor either to preliminarily heat-it or to maintain a. certain temperature' therein. Thus if any. CQ, is formed in the reaction chambers and. reaches the condensing chamber, a secondary or cleansing reaction will necessarily ensue in. passing through the bed ref sistor7 whereby only clean fume and CO will enter the rod battery, and if no additional CU2 or air 'thereafter .reaches the' Vlower portions ot' the condensing chamber all ol the tunic can be' regained in the form of liquid zinc. '.lhe up series of rods which como in contact with the coke may he ot carborunduin to prevent free conduction of current into the body of rods beneath..

llllien the secondary reactionv is require(y 'the coke 'will need occasional renewals. To recintato this the lower series of covertiles -or slabs 37 is rovided with ports or openings 38 and the overlying bricks may he advantageously cut to produce a wedgelike section 39. By removing the'latter the ing. a flat door uponfwhicha considerable" quantity reservo charge `rnaterial may vbe stored rais also to iznoduee'a very perect--sir or the jointed 'hriclr wor.

aber e the Gbviioasly any cross `nal :iorm of rods may be nsedin tl' eibattery, such as square orA hef spacing he sample, the narrors'er or vice versa, or. hu diameters the ro may progressively@ @creased or decreased, as may be' desire-tl. This olf cross-disponi and also 'the alter- J of rods can be availed l i vast nui ber of impingements, deflections and turnhlings .of the funie'and gas; contact with a relatively immense snper'lial condensing surface on member having the best known characteristics for the withdrawal oi' stored lica and all of the above features cooperate to attract and coaleece the minute primary mist-drops into zincepheres oi' sensible Adimensions which will subsequently roll oil1 the rods and gravitate into the bail Again, should portions of tlie comiensing system become cold @noun-lr to cliill the fume sav .about 775 b Y 7 c 5 no air or C02 being present, tlien this product. will not lie the .eo-called bluepowder l (oxidized)I oi ccnnnerce but congealecl spheres of nnoxfflizecl metal which can be inscri and run tog-ether in the bath..

.in stolrinif the charge the liest results are etant also e .high input of energyfwliicli ie a, .first requisite for their eiiicient performance. f

..llhe tiisposal of .ie condenser between two longitudinal resistors is a feature which is regarded oi Lfrime importance in tllatvvthe heat insulation at, its sides may be .Said to be practica ly perfect7 thereby forcing all ci the 'volatile precincts of the reaction and nearly all of the heat storecl therein to flow 'ogieticr in a ccninion downward direction5 l, .to the Zine bath Who-Sc temperature ie controllable. The reaction Setnp by the coinon of Zn----l-lieat is endotliermic function of temperature, of calories Linie acting niion a rclativel)Y highly -en.t1'eled or compact. mass; but the volw tilizefl precincts thereof v(theoretically inwlncli the intent heat oi vapori- .'Jation are stored, are very voluminous.

Consequently it is essential that. the velocity of iow sliali loe low, which means a slight friction lieocl. and that ample 'timc'sliall be eornied for the absorption and conveyance away of the floating heatunits. To take temperature ont of a gas is inversely analoirons, say, to imparting temperature to air. the pre cnt system. inversely 'follows in principle: what laas been abundantly proven ne moet eiiieetiv in the recu'ieration ci air i'er re'vcrlie tmf.' furnaces; that is, die air 'to lie licat. is; iinpelicfl or lli-nvr throng-:i1 a System ci.

` nreviensly l* l* sniiggcred roes can the direct nnpnge vresistors with in the resistor Support or ments necessary to Wi'i ioni'. Such a. velocity of iiow as would defeat the function plug/'eel by time and also produce euch z, baclr'pressurej `would interfere with and retard the primary reaction.

Another advantage of yusing; coniponnri an interposed condenser that the furnace a wliole readily be designed to approximate a Square in. plan, wherein the outer raoliatinge-wv ice becomes a minimum, but it will be Olivierithat the 'furnace is an operative element iii either of 'the resistors are omitted.

Various moelicntions might lic indicated., but these have been purposely Cistor resting upon sido Supports containing traneverse ports with. an nitervcning "rough or Sump. ln nn electric zinc furnace, rcsiaior resting upon .eide supporte, lower face being exposed to. an und trough or sump and. its upper and side Sur- 'facce being incascd.

An electric furnace having; outer walls set to forni a gallery or galleries ext-entlalong;l the outer side or sides, olz an inclosed resistor, and ports in sfxifl walls axial alineincn; with corresponding' 1,.;

supports. an electric .Zinc furnace, :in .incleeecl vroel-reeistor or resistors whose casing or casngs are sheathed with tlie material 'Le be charged.

6. An electric :eine furnace haring; a rociesistor, open below and inclorsetl above5 and System of ports through which tlie c s stoked into a space beneath the expo oWer face of said resistor.

T. An electric zinc furnace having a roclresistor, open 'below nml incloscn'l aber@ with a system oi cliargostolring ports, enel a vertical gallery arranged to .supplyA fresh charging material.

n electric zinc furnace haring* rociresistor, open below anni inclosefl above, with a system ci' charge-staking ports anti a. Vertical gallery, the reserve charge insitel rinl acting as a seal againct the entry of nir to or tlic enit of vaporizecl products from the reaction chamber. f

S. in an electric zinc furnace. c roil-rc-- Sister Whose lower series of Poils exposed to the reaction chamber7 i'lic said rods or oini! te@ 7 resti ing upon the general. statement that the inmisma@ 5 e to :imcii :iwim fu or dmxid. 0f carbon. mg fha rate of evolution of the fume D l0. in electric zine furnace heffing a m und gas. l 55 resisorwhieh has me layer serifis of iodfs i 17. n an eectrc zinc furnace, :1 con unify' eeciricaly nnn-Qonductiv@ :mci use? ineiposed between parallel reaction other 0r seam/uffi laye? Gr hay .ms which chaizvi'oere and consi'uce 'o receive all of A. @Metric 'Bl' h Earth im 122i. in :an sii beneath the L th where?? 1 ih@ iemfiaratme D. HAROLD BU 

